Chapter XIII: Warping, Beaming and Dressing

There are a few distinct methods of preparing warp threads on the weaver's beam. Stated briefly, the chief methods are--

1. The warp is made in the form of a chain on a warping mill, and when the completed chain is removed from the mill it is transferred on to the weaver's beam.

2. The warp is made in the form of a chain on a linking machine, and then beamed on to a weaver's beam.

3. The warp yarns are wound or beamed direct from the large cylindrical "rolls" or "spools" on to a weaver's beam.

4. The warp yarns are starched, dried and beamed simultaneously on to a weaver's beam.

The last method is the most extensively adapted; but we shall describe the four processes briefly, and in the order mentioned.

For mill warping, as in No. 1 method, from 50 to 72 full spinning bobbins are placed in the bank or creel as illustrated to the right of each large circular warping mill in Fig. 27. The ends of the threads from these bobbins are drawn through the eyes of two leaves of the "heck," and all the ends tied together. The heck, or apparatus for forming what is known as the weaver's lease, drawer's lease, or thread-by-thread lease, is shown clearly between the bobbin bank and the female warper in the foreground of the illustration. The heck is suspended by means of cords, or chains, and so ranged that when the warping mill is rotated in one direction the heck is lowered gradually between suitable slides, while when the mill is rotated in the opposite direction the heck is raised gradually between the same slides. These movements are necessary in order that the threads from the bobbins may be arranged spirally round the mill and as illustrated clearly on all the mills in the figure. The particular method of arranging the ropes, or the gearing if chains are used, determines the distance between each pair of spirals; a common distance is about 1-1/2 in. There are about 42 spirals or rounds on the nearest mill in Fig. 27, and this number multiplied by the circumference of the mill represents the length of the warp.

At the commencement, the heck is at the top, and when the weaver's lease has been formed on the three pins near the top of the mill with the 50 to 72 threads (often 56), the mill is rotated by means of the handle and its connections shown near the bottom of the mill. As the mill rotates, the heck with the threads descends gradually and thus the group of threads is disposed spirally on the vertical spokes of the mill until the desired length of the warp is reached. A beamer's lease or "pin lease" is now made on the two lower pegs; there may be two, three, four or more threads in each group of the pin lease; a common number is 7 to 9. When this pin lease has been formed, one section of the warp has been made, the proportion finished being (50 to 72)/x where x is the total number of threads required for the cloth. The same kind of lease must again be made on the same two pins at the bottom for the beginning of the next section of 50 to 72 threads, and the mill rotated in the opposite direction in order to draw up the heck, and to cause the second group of 50 to 72 threads to be arranged spirally and in close touch with the threads of the first group. When the heck reaches the top of the mill, the single-thread lease is again made, all the threads passed round the end pin, and then all is ready for repeating the same two operations until the requisite number of threads has been introduced on to the mill. If it is impossible to accommodate all the threads for the cloth on the mill, the warp is made in two or more parts or chains. It will be noticed that the heck for the nearest mill is opposite about the 12th round of threads from the bobbin, whereas the heck for the second mill is about the same distance from the top. A completed warp or chain is being bundled up opposite the third mill. When the warp is completed it is pulled off the mill and simultaneously linked into a chain.

A very similar kind of warp can be made more quickly, and often better, on what is termed the linking machine mentioned in No. 2 method. Such a machine is illustrated in Fig. 28, and the full equipment demands the following four distinct kinds of apparatus--a bank capable of holding approximately 300 spools, a frame for forming the weaver's lease and the beamer's lease, machine for drawing the threads from the spools in the bank and for measuring the length and marking the warp at predetermined intervals, and finally the actual machine which links the group of threads in the form of a chain.

In Fig. 28 part of the large bank, with a few rows of spools, is shown in the extreme background. The two sets of threads, from the two wings of the bank, are seen distinctly, and the machine or frame immediately in front of the bank is where the two kinds of lease are made when desired, i.e. at the beginning and at the end of the warp. Between this leasing frame and the linking machine proper, shown in the foreground, is the drawing, measuring and marking machine. Only part of this machine is seen--the driving pulleys and part of the frame adjoining them. All these frames and machines are necessary, but the movements embodied in them, or the functions which they perform, are really subsidiary to those of the linker shown in the foreground of Fig. 28.

Although the linking machine is composed of only a few parts, it is a highly-ingenious combination of mechanical parts; these parts convert the straight running group of 300 threads into a linked chain, and the latter is shown distinctly descending from the chute on to the floor in the figure. Precisely the same kind of link is made by the hand wrappers when the warps indicated in Fig. 27 are being withdrawn from the mills. Two completed chains are shown tied up in Fig. 28, and a stock of rolls or spools appear against the wall near the bank.

The completed chain from the warping mill or the linking machine is now taken to the beaming frame, and after the threads, or rather the small groups of threads, in the pin lease have been disposed in a kind of coarse comb or reed, termed an veneer or radial, and arranged to occupy the desired width in the veneer, they are attached in some suitable way to the weaver's beam. The chain is held taut, and weights applied to the presser on the beam while the latter is rotated. In this way a solid compact beam of yarn is obtained. The end of the warp--that one that goes on to the beam last--contains the weaver's lease, and when the completed beam is removed from the beaming or winding-on frame, this single-thread lease enables the next operative to select the threads individually and to draw the threads, usually single, but sometimes in pairs, in which case the lease would be in pairs, through the eyes of the camas or HEALDS, or to select them for the purpose of tying them to the ends of the warp in the loom, that is to the "thrum" of a cloth which has been completed.

Instead of first making a warp or chain on the warping mill, or on the linking machine, and then beaming such warp on to the weaver's beam or loom beam as already described, two otherwise distinct processes of warping and beaming may be conducted simultaneously. Thus, the total number of threads required for the manufacture of any particular kind of cloth--unless the number of threads happens to be very high--may be wound on to the loom beam direct from the spools. Say, for example, a warp was required to be 600 yards long, and that there should be 500 threads in all. Five hundred spools of warp yarn would be placed in the two wings of a V-shaped bank, and the threads from these spools taken in regular order, and threaded through the splits or openings of a reed which is placed in a suitable position in regard to the winding-on mechanism. Some of the machines which perform the winding-on of the yarn are comparatively simple, while others are more or less complicated. In some the loom beam rotates at a fixed number of revolutions per minute, while in others the beam rotates at a gradually decreasing number of revolutions per minute. One of the latter types made by MESSRS Urquhart, Lindsay & Co., Ltd., Dundee, is illustrated in Fig. 29, and the mechanism displayed is identical with that employed for No. 4 method of preparing warps.

The V-shaped bank with its complement of spools (500 in our example) would occupy a position immediately to the left of Fig. 29. The threads would pass through a reed and then in a straight wide sheet between the pair of rollers, these parts being contained in the supplementary frame on the left. A similar frame appears on the extreme right of the figure, and this would be used in conjunction with another V-shaped bank, not shown, but which would occupy a position further to the right, i.e. if one bank was not large enough to hold the required number of spools. The part on the extreme right can be ignored at present.

The threads are arranged in exactly the same way as indicated in Fig. 28 from the bank to the reed in front of the rollers in Fig. 29, and on emerging from the pair of rollers are taken across the stretch between the supplementary frame and the main central frame, and attached to the weavers beam just below the pressing rollers. It may be advisable to have another reed just before the beam, so that the width occupied by the threads in the beam may be exactly the same as the width between the two flanges of the loom beam.

The speed of the threads is determined by the surface speed of the two rollers in the supplementary frame, the bottom roller being positively driven from the central part through the long horizontal shaft and a train of wheels caged in as shown. The loom beam, which is seen clearly immediately below the pressing rollers, is driven by friction because the surface speed of the yarn must be constant; hence, as the diameter over the yarn on the beam increases, the revolutions per minute of the beam must decrease, and a varying amount of slip takes place between the friction-discs and their flannels.

As the loom beam rotates, the threads are arranged in layers between the flanges of the loom beam. Thus, the 500 threads would be arranged side by side, perhaps for a width of 45 to 46 in., and bridging the gap between the flanges of the beam; the latter is thus, to all intents and purposes, a very large bobbin upon which 500 threads are wound at the same time, instead of one thread as in the ordinary but smaller bobbin or reel. It will be understood that in the latter case the same thread moves from side to side in order to bridge the gap, whereas in the former case each thread maintains a fixed position in the width.

The last and most important method of making a warp, No. 4 method, for the weaver is that where, in addition to the simultaneous processes of warping and beaming as exemplified in the last example, all the threads are coated with some suitable kind of starch or size immediately they reach the two rollers shown in the supplementary frame in Fig. 29. The moistened threads must, however, be dried before they reach the loom beam. When a warp is starched, dried and beamed simultaneously, it is said to be "dressed."

In the modern dressing machine, such as that illustrated in Fig. 30, there are six steam-heated cylinders to dry the starched yarns before the latter reach the loom beams. Both banks, or rather part of both, can be seen in this view, from which some idea will be formed of the great length occupied. Several of the threads from the spools in the left bank are seen converging towards the back reed, then they pass between the two rollers--the bottom one of which is partially immersed in the starch trough--and forward to the second reed. After the sheet of threads leaves the second reed, it passes partially round a small guide roller, then almost wholly round each of three cylinders arranged °o°, and finally on to the loom beam. Each cylinder is 4 feet diameter, and three of them occupy a position between the left supplementary frame, and the central frame in Fig. 29, while the remaining three cylinders are similarly disposed between the central frame and the supplementary frame of the right in the same illustration.

The number of steam-heated cylinders, and their diameter, depend somewhat upon the type of yarn to be dressed, and upon the speed which it is desired to run the yarn. A common speed for ordinary-sized jute is from 18 to 22 yards per minute.

A different way of arranging the cylinders is exemplified in Fig. 31. This view, which illustrates a machine made by Messrs. Charles Parker, Sons & Co., Dundee, has been introduced to show that if the warps under preparation contain a comparatively few threads, or if the banks are made larger than usual, two warps may be dressed at the same time. In such a case, three cylinders only would be used for each warp, and the arrangement would be equivalent to two single dressing machines. The two weaver's beams, with their pressing rollers, are shown plainly in the centre of the illustration. Some machines have four cylinders, others have six, while a few have eight. A very similar machine to that illustrated in Fig. 31 is made so that all the six cylinders may be used to dry yarns from two banks, and all the yarns wound on to one weaver's beam, or all the yarns may be wound on to one of the beams in the machine in Fig. 31 if the number of threads is too many for one bank.

Suppose it is desired to make a warp of 700 threads instead of 500, as in the above example; then 350 spools would be placed in each of the two banks, the threads disposed as already described to use as much of the heating surface of the cylinder as possible, and one sheet of threads passed partially round what is known as a measuring roller. Both sheets of threads unite into one sheet at the centre of the machine in Fig. 31, and pass in this form on to one of the loom beams.

It has already been stated that the lower roller in the starch box is positively driven by suitable mechanism from the central part of the machine, Fig. 29, while the upper roller, see Fig. 30, is a pressing roller and is covered with cloth, usually of a flannel type. Between the two rollers the sheet of 350 threads passes, becomes impregnated with the starch which is drawn up by the surface of the lower roller, and the superfluous quantity is squeezed out and returns to the trough, or joins that which is already moving upwards towards the nip of the rollers. The yarn emerges from the rollers and over the cylinders at a constant speed, which may be chosen to suit existing conditions, and it must also be wound on to the loom beam at the same rate. But since the diameter of the beam increases each revolution by approximately twice the diameter of the thread, it is necessary to drive the beam by some kind of differential motion.

The usual way in machines for dressing jute yarns is to drive the beam support and the beam by means of friction plates. A certain amount of slip is always taking place--the drive is designed for this purpose--and the friction plates are adjusted by the yarn dresser during the operation of dressing to enable them to draw forward the beam, and to slip in infinitesimal sections, so that the yarn is drawn forward continuously and at uniform speed.

During the operation, the measuring roller and its subsequent train of wheels and shafts indicates the length of yarn which has passed over, also the number of "cuts" or "pieces" of any desired length; in addition, part of the measuring and marking mechanism uses an ink-pad to mark the yarn at the end of each cut, such mark to act as a guide for the weaver, and to indicate the length of warp which has been woven. Thus if the above warp were intended to be five cuts, each 120 yards, or 600 yards in all, the above apparatus would measure and indicate the yards and cuts, and would introduce a mark at intervals of 120 yards on some of the threads. And all this is done without stopping the machine. At the time of marking, or immediately before or after, just as desired, a bell is made to ring automatically so that the attendant is warned when the mark on the warp is about to approach the loom beam. This bell is shown in Fig. 29, near the right-hand curved outer surface of the central frame.

As in hand warping or in linking, a single-thread lease is made at the end of the desired length of warp, or else what is known as a pair of "clasp-rods" is arranged to grip the sheet of warp threads.

After the loom beam, with its length of warp, has been removed from the machine, the threads are either drawn through the eyes or mails of the cambs (termed gears, healds or heddles in other districts) and through the weaving reed, or else they are tied to the ends of the threads of the previous warp which, with the weft, has been woven into cloth. These latter threads are still intact in the cambs and reed in the loom.